Cell surface glycoproteins have been shown to undergo changes during cellular transformation and when normal cells enter the stationary phase of growth. They have also been implicated as being involved in cellular migration and recognition, cell adhesion, and cell-cell communication. This research will be directed to a study of the structure and especially the biosynthesis of cell membrane glycoproteins. These studies will also provide information as to the mechanisms and the control of enzymes that catalyze glycosyltransfer to cell surface glycoproteins. Some of the specific questions to be answered are: a) What are the mechanisms by which sugars are incorporated into glycoproteins? b) How specific are these enzymes in regard to glycosyl-donors and acceptors? c) What control mechanisms, if any, regulate these enzymes? d) How do normal and transformed cells differ in regard to the above? Answers to these questions will enable an experimental attack on the role of these glycoproteins in cell transformation, regulation and development, in intercellular communication, and as part of the extracellular matrix.